Baby humpback whales are born in places we didn't expect

Humpback whales have long been thought to give birth in tropical waters, like the Great Barrier Reef. But sightings of newborn calves stretching all the way down to Tasmania are changing that narrative.

The sightings of baby humpback whales suggest that some mothers are giving birth over 1,500 kilometers south of the expected calving grounds.

Scientists from UNSW Sydney led the study that brought this discovery to light. The research was based on over 200 calf sightings reported by whale watching operators, government wildlife agencies, and everyday observers.

The sightings span from Queensland down to Tasmania and even across to New Zealand’s South Island. The findings challenge what we thought we knew about where these giant creatures begin their lives.

Baby humpback whale sightings

The idea for this research began when PhD candidate and whale watching skipper Jane McPhee-Frew saw something unusual off the coast of Newcastle.

“I was working part-time as a skipper on a whale-watching boat in Newcastle when I first spotted a calf in the area,” said McPhee-Frew.

“It seemed out of place. The calf was tiny, obviously brand new. What were they doing here? But none of my tourism colleagues seemed surprised.”

That moment led to conversations with research colleagues. McPhee-Frew discovered there was a gap between what science had recorded and what people out on the water were witnessing.

“Eventually, we just ran out of land to see them from. So we don’t actually know where the limit is. But we had reports right to the bottom of Tassie, the southernmost points of Western Australia and to the South Island of New Zealand.”

Whales in the danger zone

The first sighting in Newcastle came in a very busy shipping area – home to the largest coal export port on Earth. Many of the calf sightings in the study were recorded from 2016 onwards, with the bulk of them happening in 2023 and 2024.

“It’s not just the sightings themselves that are important,” noted McPhee-Frew. “The pattern we’re seeing is mother whales with calves travelling through some of the busiest shipping lanes and urbanised regions.

“This means these vulnerable animals are exposed to risks like boat strikes, entanglements, pollution – and just general public unawareness.”

Threats to baby humpback whales

Humpback whales were nearly wiped out in the 1960s. Conservation efforts have since helped their numbers bounce back to an estimated 50,000 today.

While the idea of baby humpback whales being born this far south may sound new, McPhee-Frew thinks it might be an old habit we’re only now seeing again.

She explored 19th-century whaling logs and old expedition notes that included reports of calves and mothers in similar southern locations.

The low population after decades of industrial whaling might have made this behavior invisible for years. Now, thanks to drones, social media, and booming whale tourism, people are noticing more than ever before.

According to McPhee-Frew, it’s vital to raise awareness about the dangers these young whales face as they travel thousands of kilometers north.

“Regardless of the health of population now, we can’t be in a situation where we’re putting any age of whales – especially baby whales – in a situation where they’re getting caught in nets, being exposed to chemicals, being hit by boats and being harassed.”

Newborns in busy shipping lanes

Study co-author Professor Tracey Rogers noted that newborn whales face unique challenges.

“Newborns are like Great Dane puppies. They have those long, enormous fins that they need to grow into, and they’re not very strong swimmers. So they rest a lot of the time on their mum’s back,” said Professor Rogers.

“Imagine giving birth off Hobart and then swimming up the coast. It’s heartbreaking to think of these young whales traveling through busy ports and dangerous shipping lanes with those long, clumsy fins.”

“And it’s not just happening here in NSW – this is off WA, Victoria, Tasmania, New Zealand – it’s something we just didn’t know before.”

Protecting humpback whales

Dr Adelaide Dedden from the NSW National Parks and Wildlife Service says that while laws exist to protect humpbacks, many water users still aren’t aware of them.

“The legislation to protect humpback whales, including mothers and calves, is already in place across all states,” said Dr Dedden. “But we do have a gap in public awareness, particularly among recreational water users.”

“People need to be aware that calves are being seen not just on the southern migration but also on the northern one.”

Close-up photos may make it seem like baby whales are easy to spot, but these moments are rare and should happen on the whales’ terms – not because a boat got too close.

“Humpbacks are charismatic and curious,” said Dr Dedden. “They’re going to want to come and check out the boat.”

The recommended distance is 100 meters from adult whales and 300 meters from a mother-calf pair.

“We’ve been working hard to get this message out to the public and encourage boaters, surfers, kayakers and jet-ski operators to be aware of these guidelines,” noted Dr Dedden.

Excitement and curiosity about whales

According to McPhee-Frew, collaboration between scientists, government agencies, tourism operators, and the public has made this research possible.

Whale watching crews often spot calves and pass on vital information. They also help educate the public on how to safely enjoy watching whales.

Social media platforms have played a big role too. Photos and sightings shared by users help track where whales are seen – and when.

“The excitement and curiosity around whales are contagious,” said McPhee-Frew. “We’ve built a huge repository of data just by encouraging the public to share observations.”

Many questions remain

There’s still one big question that remains. Why are the mothers still traveling north after giving birth, especially when food is so scarce in tropical waters?

McPhee-Frew suggests we need to rethink the idea that whale migration has fixed start and end points. Maybe whales use different environments in different ways.

“We still have a lot to learn. But, you know what? It’s such a privilege to see whales. It is such a fantastic aspect of living in Australia. We just need to follow the rules so everyone can enjoy.”

The full study was published in the journal Frontiers in Marine Science.

Image Credit: © Vanessa Risku (Instagram: @droning_my_sorrows)

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